Yes there is, it is poecilonym. Note however that this word is not in modern use, and can not be found in most modern dictionaries. Of course, you can still use it to impress your friends.
yucky is another word
A word that has the same meaning as another word is a synonym.
That is called a synonym.
synonym
An synonym is a word with the almost same meaning as another word.
there is a synonym of the word synonym it is poecilonym
A synonym is a word that means the same as another word. So you have to have TWO words to compare. Yearn cannot be a synonym all by itself. It has to be a synonym of another word.
A synonym is a word that has an identical or very similar meaning to another word. As freshwaterbiome is not a word it does not have a synonym.
A synonym is a word that means the same thing as another word. An antonym is a word that means the opposite of another word. You can't describe a word as a synonym or an antonym without having another word to compare it to.
Brother can be a synonym for sibling, yes. A synonym is a word that means the same thing as another word.
A word cannot be discusses as a synonym or antonym on its own. A word is only a synonym or antonym with respect to another word.
Synonym
A synonym is a word that has a similar meaning to another word. Eg. Correct and right
yucky is another word
An synonym is another word meaning the same as another. Synonyms can be found in a dictionary, and in a thesaurus. The synonym for the word passion are affection, devotion, and fondness.
A word that has the same meaning as another word is a synonym.
A synonym is a word that means the same, or almost the same. So yes the word absurd could be a synonym form another word or there are synonyms for the word absurd.